The present invention relates to a method of manufacture of a semiconductor device and a to semiconductor device; and, more particularly, the invention relates to a technique that is effective when applied to a method of manufacture of a semiconductor device and a to semiconductor device which use, as an interconnect material, a conductor film composed mainly of copper.
An inlaid interconnect structure is formed based on a metallization technique, called a damascene process, by embedding an interconnect material in an interconnect opening portion, such as an interconnect trench or hole, formed in an insulating film. When the main interconnect material is copper, however, it tends to be more easily diffused in an insulating film compared with another metal, such as aluminum. Thus, diffusion of copper from the inlaid interconnect into an insulating film has been suppressed or prevented by interposing a thin conductive barrier film between the interconnect forming conductor film composed mainly of copper and the insulating film.
A technique relating to a barrier metal film of a semiconductor device is described, for example, in Japanese Unexamined Patent Publication No. Hei 11(1999)-233631. This publication discloses a technique for forming a contact hole in an interlevel insulating film, and then forming a multilayer barrier metal film in the contact hole and over the interlevel insulating film by using PVD and CVD in combination. On the other hand, Japanese Unexamined Patent Publication No. 2000-40672 discloses a technique for forming a conductive barrier film by using tantalum (Ta) and tantalum nitride (TaN).